OnePlus was founded on 16 December 2013 by former Oppo vice-president Pete Lau (刘作虎) and Carl Pei (裴宇). According to the Chinese government's documentation, the only institutional stockholder in OnePlus is Oppo. Although Lau initially denied that OnePlus was a wholly owned subsidiary of Oppo, upon release of the regulatory filings they admitted that they are owned by Oppo and are "in talks with other investors" (although nothing has been announced to date). The company's main goal was to design a smartphone that would balance high-end quality with a lower price than other phones in its class, believing that users would "Never Settle" (Chinese: 不将就) for the lower-quality devices produced by other companies. Lau explained that "we will never be different just for the sake of being different. Everything done has to improve the actual user experience in day-to-day use." He also showed aspirations of being the "Muji of the tech industry", emphasizing its focus on high-quality products with simplistic, user-friendly designs. Continuing Lau's association with the platform from the Oppo N1, OnePlus entered into an exclusive licensing agreement with Cyanogen Inc. to base its products' Android distribution upon a variant of the popular custom ROM CyanogenMod and use its trademarks outside of China.
The company unveiled its first device, the OnePlus One, on 23 April 2014. In December 2014, alongside the release of the OnePlus One in India exclusively through Amazon, OnePlus also announced plans to establish a presence in the country, with plans to open 25 official walk-in service centres across India.
OnePlus made its products available in Southeast Asia for the first time, partnering with Lazada Indonesia on 23 January 2015 and is expected to expand during this year throughout the region.
In April 2014, OnePlus hired Han Han as the product ambassador in mainland China.
On 9 March 2014 the company decided to expand its operations to all European countries except Switzerland (although OnePlus devices can be purchased in Switzerland via local online retailers), serving now 43 countries and regions all over the world. As of March 2016, OnePlus serves for the following countries and regions: Austria, Belgium, Bulgaria, Canada, Mainland China, Croatia, Cyprus, Czech Republic, Denmark, Egypt, Estonia, Finland, France, Germany, Greece, Hong Kong, Hungary, India, Ireland, Israel, Italy, Latvia, Lithuania, Luxembourg, Malta, Malaysia, Netherlands, Poland, Portugal, Romania, Saudi Arabia, Singapore, Spain, Slovakia, Slovenia, Sweden, the United Arab Emirates, the United Kingdom and the United States.
- OnePlus One (codename "bacon"; unveiled on 23 April 2014; international release on 6 June 2014)
- OnePlus 2 (codename "oneplus2"; unveiled on 27 July 2015; international release on 11 August 2015)
- OnePlus X (codename "onyx"; unveiled on 29 October 2015; international release on 5 November 2015)
- OnePlus 3 (codename "oneplus3"; unveiled on 14 June 2016; international release on 14 June 2016)
- OnePlus 3T (codename "oneplus3t"; unveiled on 15 November 2016; international release on 28 November 2016)
- OnePlus 5 (codename "cheeseburger"; unveiled on 20 June 2017; international release on 27 June 2017)
- OnePlus 5T (codename "dumpling"; unveiled on 16 November 2017; international release on 21 November 2017)